MyBatis的一个主要的特点就是需要程序员自己编写sql，那么如果表太多的话，难免会很麻烦，所以mybatis官方提供了一个逆向工程，可以针对单表自动生成mybatis执行所需要的代码（包括mapper.xml、mapper.java、po..）。一般在开发中，常用的逆向工程方式是通过数据库的表生成代码。
/nxgouwu/src/main/resources/sqlMapGenerator.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
<generatorConfiguration>
    <!-- 配置属性文件，这样有变更只需改配置文件 -->
    <properties resource="generatorConfig.properties" />
    <!-- 制定mysql的驱动包的路径 千万别放中文路径下 -->
    <classPathEntry
        location="D:\maven\repository\mysql\mysql-connector-java\5.1.40\mysql-connector-java-5.1.40.jar" />
    <!-- 配置数据源和生成的代码所存放的位置 -->
    <context id="company">
        <!-- 是否生成注释 true不生成 false生成 -->
        <commentGenerator>
            <property name="suppressAllComments" value="${suppressAllComments}" />
        </commentGenerator>
        <jdbcConnection driverClass="${driverClass}"
            connectionURL="${url}" userId="${username}" password="${password}" />
        <!-- 所生成的实体类的位置默认资源包src -->
        <javaModelGenerator targetPackage="${modeltargetPackage}"
            targetProject="${targetProject}" />
        <!-- 所生成的sqlMap的影射文件的位置,默认资源包src -->
        <sqlMapGenerator targetPackage="${sqltargetPackage}"
            targetProject="${targetProject}/src/main/resources" />
        <javaClientGenerator targetPackage="${clienttargetPackage}"
            targetProject="${targetProject}" type="XMLMAPPER" />


        <!-- 为哪些表生成代码 tableName:表名 schema:不用填写 -->
        <table schema="" tableName="orders"  enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"/>
        <table schema="" tableName="user_info" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"/>
        <table schema="" tableName="user_extra" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"/>

    </context>
</generatorConfiguration>

/nxgouwu/src/main/resources/generatorConfig.properties

suppressAllComments=true
driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/gouwu?characterEncoding=utf-8
username=root
password=g
modeltargetPackage=pojo
targetProject=nxgouwu
sqltargetPackage=mapper
clienttargetPackage=dao

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.spoon</groupId>
  <artifactId>nxgouwu</artifactId>
  <version>0.0.1-SNAPSHOT</version>
<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <dependencies>
        <!--添加mysql驱动程序依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.40</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.2.8</version>
        </dependency>
        <!--日志包依赖 -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>